| 摘要 |
<p>PURPOSE:To construct a sludge circulating tank and a settling tank in one body and to enable concentration of sludge also by suspending an internal cylinder provided with an overflow weir in a sludge circulating tank wherein an inverted circular truncated conical weir and a double surface rake for collecting and discharging sludge are installed below the internal cylinder. CONSTITUTION:An internal cylinder 2 having an overflow weir 6 is suspended by an appropriate method in a sludge circulating tank 1 wherein activated sludge is suspended by an aeration device 5. The suspended sludge is settled in the internal cylinder 2. By this constitution, waste water fed to the sludge circulating tank 1 is adsorbed to the activated sludge and decomposed; the activated sludge is settled in the internal cylinder 2 and supernatant water flows over an overflow weir 6 and recovered as treated water. The settled sludge is gathered to the centeral part by a double surface rake 4 having sludge collecting function at the inside of an inverted truncated conical weir 3 and sludge discharging function ranging to the outside of the internal cylinder 2 at the outside of the weir 3, and the gathered sludge is concentrated. The concentrated sludge is overflowed over an upper end of the weir 3, and uitilized again as activated sludge.</p> |
